SE DMA mode can be used for larger transfers and FIFO mode
for smaller transfers.
Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@xxxxxxxxxxx>
---
v4 -> v3:
- remove cur_m_cmd field
- add dma_addr fields to spi_geni_master
- dont use dma_addr from xfer, use above
- dev_warn instead of dev_err in handle_timeout
- set xfer_mode to FIFO in set_cs
v2 -> v3:
- indentation change
- readability change
v1 -> v2:
- replace writel_relaxed with writel
- corrected order of performing FSM reset and dma_unprep
- added more comments in geni_can_dma
- removed redundant change in spi_geni_init(DMA as default xfer_mode)
- removed redundant initialisations in setup_se_xfer
- removed redundant null checks in setup_se_xfer
- added dma_tx_prep failure handling(rx un_map) in setup_se_xfer
- move handing return of setip_se_xfer to transfer_one
- apply irq error handling for DMA mode too in geni_spi_isr
---
drivers/spi/spi-geni-qcom.c | 211 ++++++++++++++++++++++++++++++++++----------
1 file changed, 165 insertions(+), 46 deletions(-)
diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
index 4e83cc5..e1b2e0b 100644
--- a/drivers/spi/spi-geni-qcom.c
+++ b/drivers/spi/spi-geni-qcom.c
@@ -87,6 +87,8 @@ struct spi_geni_master {
struct completion cs_done;
struct completion cancel_done;
struct completion abort_done;
+ struct completion tx_reset_done;
+ struct completion rx_reset_done;
unsigned int oversampling;
spinlock_t lock;
int irq;
@@ -95,6 +97,8 @@ struct spi_geni_master {
struct dma_chan *tx;
struct dma_chan *rx;
int cur_xfer_mode;
+ dma_addr_t tx_se_dma;
+ dma_addr_t rx_se_dma;
};
static int get_spi_clk_cfg(unsigned int speed_hz,
@@ -129,23 +133,27 @@ static int get_spi_clk_cfg(unsigned int speed_hz,
return ret;
}
-static void handle_fifo_timeout(struct spi_master *spi,
+static void handle_se_timeout(struct spi_master *spi,
struct spi_message *msg)
{
struct spi_geni_master *mas = spi_master_get_devdata(spi);
unsigned long time_left;
struct geni_se *se = &mas->se;
+ const struct spi_transfer *xfer;
spin_lock_irq(&mas->lock);
reinit_completion(&mas->cancel_done);
- writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
+ if (mas->cur_xfer_mode == GENI_SE_FIFO)
+ writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
+
+ xfer = mas->cur_xfer;
mas->cur_xfer = NULL;
geni_se_cancel_m_cmd(se);
spin_unlock_irq(&mas->lock);
time_left = wait_for_completion_timeout(&mas->cancel_done, HZ);
if (time_left)
- return;
+ goto unmap_if_dma;
spin_lock_irq(&mas->lock);
reinit_completion(&mas->abort_done);
@@ -162,6 +170,39 @@ static void handle_fifo_timeout(struct spi_master *spi,
*/
mas->abort_failed = true;
}
+
+unmap_if_dma:
+ if (mas->cur_xfer_mode == GENI_SE_DMA) {
+ if (xfer) {
+ if (xfer->tx_buf && mas->tx_se_dma) {
+ spin_lock_irq(&mas->lock);
+ reinit_completion(&mas->tx_reset_done);
+ writel(1, se->base + SE_DMA_TX_FSM_RST);
+ spin_unlock_irq(&mas->lock);
+ time_left = wait_for_completion_timeout(&mas->tx_reset_done, HZ);
+ if (!time_left)
+ dev_err(mas->dev, "DMA TX RESET failed\n");
+ geni_se_tx_dma_unprep(se, mas->tx_se_dma, xfer->len);
+ }
+ if (xfer->rx_buf && mas->rx_se_dma) {
+ spin_lock_irq(&mas->lock);
+ reinit_completion(&mas->rx_reset_done);
+ writel(1, se->base + SE_DMA_RX_FSM_RST);
+ spin_unlock_irq(&mas->lock);
+ time_left = wait_for_completion_timeout(&mas->rx_reset_done, HZ);
+ if (!time_left)
+ dev_err(mas->dev, "DMA RX RESET failed\n");
+ geni_se_rx_dma_unprep(se, mas->rx_se_dma, xfer->len);
+ }
+ } else {
+ /*
+ * This can happen if a timeout happened and we had to wait
+ * for lock in this function because isr was holding the lock
+ * and handling transfer completion at that time.
+ */
+ dev_warn(mas->dev, "Cancel/Abort on completed SPI transfer\n");
+ }
+ }
}
static void handle_gpi_timeout(struct spi_master *spi, struct spi_message *msg)
@@ -178,7 +219,8 @@ static void spi_geni_handle_err(struct spi_master *spi, struct spi_message *msg)
switch (mas->cur_xfer_mode) {
case GENI_SE_FIFO:
- handle_fifo_timeout(spi, msg);
+ case GENI_SE_DMA:
+ handle_se_timeout(spi, msg);
break;
case GENI_GPI_DMA:
handle_gpi_timeout(spi, msg);
@@ -250,6 +292,8 @@ static void spi_geni_set_cs(struct spi_device *slv, bool set_flag)
}
mas->cs_flag = set_flag;
+ /* set xfer_mode to FIFO to complete cs_done in isr */
+ mas->cur_xfer_mode = GENI_SE_FIFO;
reinit_completion(&mas->cs_done);
if (set_flag)
geni_se_setup_m_cmd(se, SPI_CS_ASSERT, 0);
@@ -260,7 +304,7 @@ static void spi_geni_set_cs(struct spi_device *slv, bool set_flag)
time_left = wait_for_completion_timeout(&mas->cs_done, HZ);
if (!time_left) {
dev_warn(mas->dev, "Timeout setting chip select\n");
- handle_fifo_timeout(spi, NULL);
+ handle_se_timeout(spi, NULL);
}
exit:
@@ -482,8 +526,12 @@ static bool geni_can_dma(struct spi_controller *ctlr,
{
struct spi_geni_master *mas = spi_master_get_devdata(slv->master);
- /* check if dma is supported */
- return mas->cur_xfer_mode != GENI_SE_FIFO;
+ /*
+ * Return true if transfer needs to be mapped prior to
+ * calling transfer_one which is the case only for GPI_DMA.
+ * For SE_DMA mode, map/unmap is done in geni_se_*x_dma_prep.
+ */
+ return mas->cur_xfer_mode == GENI_GPI_DMA;
}
static int spi_geni_prepare_message(struct spi_master *spi,
@@ -494,6 +542,7 @@ static int spi_geni_prepare_message(struct spi_master *spi,
switch (mas->cur_xfer_mode) {
case GENI_SE_FIFO:
+ case GENI_SE_DMA:
if (spi_geni_is_abort_still_pending(mas))
return -EBUSY;
ret = setup_fifo_params(spi_msg->spi, spi);
@@ -597,7 +646,7 @@ static int spi_geni_init(struct spi_geni_master *mas)
break;
}
/*
- * in case of failure to get dma channel, we can still do the
+ * in case of failure to get gpi dma channel, we can still do the
* FIFO mode, so fallthrough
*/
dev_warn(mas->dev, "FIFO mode disabled, but couldn't get DMA, fall back to FIFO mode\n");
@@ -716,12 +765,12 @@ static void geni_spi_handle_rx(struct spi_geni_master *mas)
mas->rx_rem_bytes -= rx_bytes;
}
-static void setup_fifo_xfer(struct spi_transfer *xfer,
+static int setup_se_xfer(struct spi_transfer *xfer,
struct spi_geni_master *mas,
u16 mode, struct spi_master *spi)
{
u32 m_cmd = 0;
- u32 len;
+ u32 len, fifo_size;
struct geni_se *se = &mas->se;
int ret;
@@ -748,7 +797,7 @@ static void setup_fifo_xfer(struct spi_transfer *xfer,
/* Speed and bits per word can be overridden per transfer */
ret = geni_spi_set_clock_and_bw(mas, xfer->speed_hz);
if (ret)
- return;
+ return ret;
mas->tx_rem_bytes = 0;
mas->rx_rem_bytes = 0;
@@ -772,17 +821,50 @@ static void setup_fifo_xfer(struct spi_transfer *xfer,
mas->rx_rem_bytes = xfer->len;
}
+ /* Select transfer mode based on transfer length */
+ fifo_size = mas->tx_fifo_depth * mas->fifo_width_bits / mas->cur_bits_per_word;
+ mas->cur_xfer_mode = (len <= fifo_size) ? GENI_SE_FIFO : GENI_SE_DMA;
+ geni_se_select_mode(se, mas->cur_xfer_mode);
+
/*
* Lock around right before we start the transfer since our
* interrupt could come in at any time now.
*/
spin_lock_irq(&mas->lock);
geni_se_setup_m_cmd(se, m_cmd, FRAGMENTATION);
- if (m_cmd & SPI_TX_ONLY) {
+
+ if (mas->cur_xfer_mode == GENI_SE_DMA) {
+ if (m_cmd & SPI_RX_ONLY) {
+ ret = geni_se_rx_dma_prep(se, xfer->rx_buf,
+ xfer->len, &mas->rx_se_dma);
+ if (ret) {
+ dev_err(mas->dev, "Failed to setup Rx dma %d\n", ret);
+ mas->rx_se_dma = 0;
+ goto unlock_and_return;
+ }
+ }
+ if (m_cmd & SPI_TX_ONLY) {
+ ret = geni_se_tx_dma_prep(se, (void *)xfer->tx_buf,
+ xfer->len, &mas->tx_se_dma);
+ if (ret) {
+ dev_err(mas->dev, "Failed to setup Tx dma %d\n", ret);
+ mas->tx_se_dma = 0;
+ if (m_cmd & SPI_RX_ONLY) {
+ /* Unmap rx buffer if duplex transfer */
+ geni_se_rx_dma_unprep(se, mas->rx_se_dma, xfer->len);
+ mas->rx_se_dma = 0;
+ }
+ goto unlock_and_return;
+ }
+ }
+ } else if (m_cmd & SPI_TX_ONLY) {
if (geni_spi_handle_tx(mas))
writel(mas->tx_wm, se->base + SE_GENI_TX_WATERMARK_REG);
}
+
+unlock_and_return:
spin_unlock_irq(&mas->lock);
+ return ret;
}
static int spi_geni_transfer_one(struct spi_master *spi,
@@ -790,6 +872,7 @@ static int spi_geni_transfer_one(struct spi_master *spi,
struct spi_transfer *xfer)
{
struct spi_geni_master *mas = spi_master_get_devdata(spi);
+ int ret;
if (spi_geni_is_abort_still_pending(mas))
return -EBUSY;
@@ -798,9 +881,12 @@ static int spi_geni_transfer_one(struct spi_master *spi,
if (!xfer->len)
return 0;
- if (mas->cur_xfer_mode == GENI_SE_FIFO) {
- setup_fifo_xfer(xfer, mas, slv->mode, spi);
- return 1;
+ if (mas->cur_xfer_mode == GENI_SE_FIFO || mas->cur_xfer_mode == GENI_SE_DMA) {
+ ret = setup_se_xfer(xfer, mas, slv->mode, spi);
+ /* SPI framework expects +ve ret code to wait for transfer complete */
+ if (!ret)
+ ret = 1;
+ return ret;
}
return setup_gsi_xfer(xfer, mas, slv, spi);
}
@@ -823,39 +909,70 @@ static irqreturn_t geni_spi_isr(int irq, void *data)
spin_lock(&mas->lock);
- if ((m_irq & M_RX_FIFO_WATERMARK_EN) || (m_irq & M_RX_FIFO_LAST_EN))
- geni_spi_handle_rx(mas);
-
- if (m_irq & M_TX_FIFO_WATERMARK_EN)
- geni_spi_handle_tx(mas);
-
- if (m_irq & M_CMD_DONE_EN) {
- if (mas->cur_xfer) {
+ if (mas->cur_xfer_mode == GENI_SE_FIFO) {
+ if ((m_irq & M_RX_FIFO_WATERMARK_EN) || (m_irq & M_RX_FIFO_LAST_EN))
+ geni_spi_handle_rx(mas);
+
+ if (m_irq & M_TX_FIFO_WATERMARK_EN)
+ geni_spi_handle_tx(mas);
+
+ if (m_irq & M_CMD_DONE_EN) {
+ if (mas->cur_xfer) {
+ spi_finalize_current_transfer(spi);
+ mas->cur_xfer = NULL;
+ /*
+ * If this happens, then a CMD_DONE came before all the
+ * Tx buffer bytes were sent out. This is unusual, log
+ * this condition and disable the WM interrupt to
+ * prevent the system from stalling due an interrupt
+ * storm.
+ *
+ * If this happens when all Rx bytes haven't been
+ * received, log the condition. The only known time
+ * this can happen is if bits_per_word != 8 and some
+ * registers that expect xfer lengths in num spi_words
+ * weren't written correctly.
+ */
+ if (mas->tx_rem_bytes) {
+ writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
+ dev_err(mas->dev, "Premature done. tx_rem = %d bpw%d\n",
+ mas->tx_rem_bytes, mas->cur_bits_per_word);
+ }
+ if (mas->rx_rem_bytes)
+ dev_err(mas->dev, "Premature done. rx_rem = %d bpw%d\n",
+ mas->rx_rem_bytes, mas->cur_bits_per_word);
+ } else {
+ complete(&mas->cs_done);
+ }
+ }
+ } else if (mas->cur_xfer_mode == GENI_SE_DMA) {
+ const struct spi_transfer *xfer = mas->cur_xfer;
+ u32 dma_tx_status = readl_relaxed(se->base + SE_DMA_TX_IRQ_STAT);
+ u32 dma_rx_status = readl_relaxed(se->base + SE_DMA_RX_IRQ_STAT);
+
+ if (dma_tx_status)
+ writel(dma_tx_status, se->base + SE_DMA_TX_IRQ_CLR);
+ if (dma_rx_status)
+ writel(dma_rx_status, se->base + SE_DMA_RX_IRQ_CLR);
+ if (dma_tx_status & TX_DMA_DONE)
+ mas->tx_rem_bytes = 0;
+ if (dma_rx_status & RX_DMA_DONE)
+ mas->rx_rem_bytes = 0;
+ if (dma_tx_status & TX_RESET_DONE)
+ complete(&mas->tx_reset_done);
+ if (dma_rx_status & RX_RESET_DONE)
+ complete(&mas->rx_reset_done);
+ if (!mas->tx_rem_bytes && !mas->rx_rem_bytes && xfer) {
+ if (xfer->tx_buf && mas->tx_se_dma) {
+ geni_se_tx_dma_unprep(se, mas->tx_se_dma, xfer->len);
+ mas->tx_se_dma = 0;
+ }
+ if (xfer->rx_buf && mas->rx_se_dma) {
+ geni_se_rx_dma_unprep(se, mas->rx_se_dma, xfer->len);
+ mas->rx_se_dma = 0;
+ }
spi_finalize_current_transfer(spi);
mas->cur_xfer = NULL;
- /*
- * If this happens, then a CMD_DONE came before all the
- * Tx buffer bytes were sent out. This is unusual, log
- * this condition and disable the WM interrupt to
- * prevent the system from stalling due an interrupt
- * storm.
- *
- * If this happens when all Rx bytes haven't been
- * received, log the condition. The only known time
- * this can happen is if bits_per_word != 8 and some
- * registers that expect xfer lengths in num spi_words
- * weren't written correctly.
- */
- if (mas->tx_rem_bytes) {
- writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
- dev_err(mas->dev, "Premature done. tx_rem = %d bpw%d\n",
- mas->tx_rem_bytes, mas->cur_bits_per_word);
- }
- if (mas->rx_rem_bytes)
- dev_err(mas->dev, "Premature done. rx_rem = %d bpw%d\n",
- mas->rx_rem_bytes, mas->cur_bits_per_word);
- } else {
- complete(&mas->cs_done);
}
}
@@ -949,6 +1066,8 @@ static int spi_geni_probe(struct platform_device *pdev)
init_completion(&mas->cs_done);
init_completion(&mas->cancel_done);
init_completion(&mas->abort_done);
+ init_completion(&mas->tx_reset_done);
+ init_completion(&mas->rx_reset_done);
spin_lock_init(&mas->lock);
pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_set_autosuspend_delay(&pdev->dev, 250);
--
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